Excavating-machine.



e. W. KING, HJ. BARNHRT ai c. B. KING.

EXQAVATING MACHINE. APPLIGATION FILED xm. zo, 1909.

' Patented aySLww.

"G. w. Imm-H. J. BARNHART s C. B .xnt

BXGAVATING MACHINE. ArPLIoATIoH FILED 111111.20, i909.

Patented May 31, 1910.

amm,

W. KING, H. J. BARNHART an. 3.1mm.

EXCAVTING MAHINE. l ArPLIoATzoK FILED 11.13.20, 1909. f

. Patented May 31, 1910.

4 SHEETS-SHEET 3.

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G. 1y. KING, n. s. 'BARNHART a. c.

,13. KING.

1 BXGAVATING MACHINE. PrLIoATIon num 1.12.20, 1909. 959,756.

Patented May 31, 1910.

4 SHEETS-SHEET 4.

UNTTED STATES PATENT oEETcE.

GEORGE W. KING, HARRY J. BARNHART, AND CHARLES B. KNG, OF ,MARIOBL OHIO,ASSIGNORS TO THE MARION STEAM SHOVEL COMPANY, OF MARION, OHIO, A COR-PORATION OF OHIO.

EXCAVATING-MACHINE.

Specification of Letters Patent.

Patented May s1, 1910.

To (L'ZZ whom it may concern:

Be' it known that we, GEORGE 1V. KING, vHARRY J. BARNHART, and CHARLESB. KING,

citizens of the United States7 residing at Marion, in the county ofMarion and State of Ohio, have invented certain new and usefulImprovements in Excavating-Machines, o't which the following is aspecification, reference being had therein to the accompanying drawings.

This invention relates to excavating inachines, and is more particularlydesigned for use in connection with power shovels of the general Vtypeusually hnown as steam shovels.

The object of the invention is to provide such a shovel with electricaldriving means, and, to this end, it is a further object of the inventiontoprovide automatic motor controlling means whereby the motor or motorsof the,- driving mechanism will be protected against excessive currentand whereby the motor or motors will be so controlled as to cause thesaine to exert a continuous pressure or pull upon the dipper, or otherexcavating member, when excessive resistance is -otfered to the movementof that dipper or member, without the liability of the motor building upbeyond the danger point.

A further object of the invention is to provide an electrically drivenmechanism of this character which can be readily substituted for theordinary operating mechanism ot a lsteam shovel and the substitution ofwhich will require but slight alteration in thecons'triictioi'i of theshovel as a whole; further, to so arrange and combine the several partsot the operatino mechanism as to attain a high degree of efficiency,and, at thel same time, to so place the mechanism as to econoniizc spaceand distribute the weight thereof at points where it is most desirable;and further, to so arrange and locate the manual controlling devices forthe motors that the saine will be within convenient reach otthe operatorand that the operation and location ot' the same will be substantiallythe same as the. operation of the controlling devices 'for the steamshovel.

W'ith these objects in view oui'V invention consists in certain novelfeatures and in certain combinations and arrangements ot' partshereinafter tov be described, and then more particularly pointed out inthe claims.

In thel accompanying drawings,li`igure 1 is a si de elevation of a powershovel embody-y ing our invention; Fig. 2 is a top plan view ofthe same;Fig. 3 is a top plan view ofr a portion of the' boom, showing thecrowding mechanism; Fig. 4 is a conventional illustration' 'of themotor-controlling meehanisni, with the main circuit open and the mastercontroller at zero; Fig. 5 is a. similarview; with the main circuitclosed and the master controller-set for third Speed; and Fig. 6 is adetail view showing the action of the overload circuit breaker.

In these drawings we have illustrated one embodiment of our inventionand have shown the same as comprising a main trame or Acar body 1mounted upon the usual trucks' 2. The main frame is provided at itsforward end with a boom 3 so supported upon the main frame as to bemovable about a verti cal axis. An excavating member or dipper 4 issupported from the boom 3 by an arm 5 which is movaloly mounted thereon.The construction ot the shovel so far described is that of the ordinarySteam shovel, and, to substitute the electrical driving mechanism forthe steam driving mechanism the-balance wheels lo r disks are removedfrom the sha-tt 6 and the bevel gears 7 are substituted therefor. Theengines and the engine bed arealso removed and in their place aremounted two vertically arranged parallel castings or bearing plates 8,on the upper ends of which is supported a shaft 9 journaled in suitablebearings 10 and having secured thereto a' cable drinn 11 and a gear 12adapted to mesh with'a pinion 13 carriedby a shaft 14 journaled inbearings 15 formed in the castings 8 at a point beneath the bearings ofthe shaft 9. Mounted on the shaft 14 is also a gear 16 adapted to meshwith a pinion 17 carried by one end of a counter or reducing-shaft 18,on the opposite end of which is a gear 19v adapted to mesh with a pinion20 mounted on a shaft 21 of a motor 22. This motor is preferably ot theusual reversible street car type and is not shown in detail, but isindicated only by its inclosing casing. The swinging-drum'll has woundthereon a cable 23 which extends about guides 24 and about a verticaldrum 25 secured to the boom 3 and adapted to move the same aboutitsvert-ical axis when the cable is actuated. The bevel gears 7 carried bythe shaft 6 mesh with bevel pinions 26 mounted on shafts 27 'arrangedlongitudinally of themain frame 1 and having their rear ends providedwith 34 is a gear 38 which meshes with a pinion 39 mounted on a shaft 40to which is secured suitable'sprockets or driving disks 41 about whichextend driving chains 42 and 43 which also extend about thecorresponding sprocket wheels 44 and 45 on the axles of .the frontandrear trucks, respectively, whereby means are providedfor propellingthe shovel from ,one pointl to another, the druin 35 being connected' tothe shaft34 by the usual friction clutch mechanism, which is not hereshown. This operating mechanism as a. whole is the same as employed inasteam shovel withthe exception of the substituted parts comprising,principally, the bevel gears 7, pinion i 26, shafts 27 andtheir'operating motors, to.-

gether with the supporting plates or castingsl 8 and the motor foractuating the parts carried'thereby, the remaining gears and theirshafts being standard par-ts of a steam shovel. Consequently, itrequires but avery slight change to transform a steam shovel iinto anelectrically driven shovel.

Anfelectrically ydriven air'compressor 46 is mounted on the main frame 1and is connected by a pipe 47 with an air storage tank y4,8,"wliich, inturn, is connected by a piupe 49 with the cylinder 50 of a suitablebrakeol'pleratinglnechanism for the hoisting drum. This brake-operatingymechanism forms no part` of the present invention and is substantiallythe `same as that shown"l in Patent No. 666,348, granted to King andBarnhart Jany. 22, 1901, the principal difference being in thecombination of an electrically operated air compressor with thebrakefoperating mechanism. v I i The crowding mechanism is substantiallythe same as that of a steam shovel, it being modified only to such 'an'1extent, as is neces sary to applyl the electrical power thereto.

As here shown,`the arm 5 carrying the dip'- per 4 is provided withteeth` 51 which mesh .with pinions 52 carried by a shaft 53 journaled inbearings- 54. on the boom 3. This shaft is rovided on opposite sides ofthe boom' Wit gears '55 which mesh. with pinions 56 carried b Itheouterends of a counter l or reducing sha t 57 supported .on the boom 3and havingy a gear 58adapted to mesh withja pinion 59 on 'the shaftGO-Aof the motor 61. -Suitable brake-mechanism is provided forcontrolling the movement of the dipper should the motorxbecome inopf'erative or should it be desirable t0 check the movement of the dipperfor any reason. To

the motor with a drum 130 which is rigidly A this end we have providedthe shaft- 60 of secured to the shaft and about which eX- y tends abrakeband 131,4 the opposite ends of which are secured to a lever 132which is pivotally mounted on the boom 3, as shown at 133. One end ofthe band is secured to the lever at its pivotal center andthus hasnomovement relatively to the boom, while the other end of the band issecured to the lever 132 at a point removed from its piv;- otal center,whereby the movement of the lever about its pivotal center will causethe brake band to be tightened about the drum and to resistitsinovement. The lever 132. I

is connected by means of a' rod 134 to one arm .of a bell crank lever135 which is pivotally mounted on the boom 3 at 136 andhas its other armprovided with a foot plate 137. A weight 138 is secured tothe be'llcrank lever on that side of its pivotal center opposite the foot plate137 `in such a manner as to hold the foot plate normally raised and thusmaintaining thebrake band in its inoperative position.. The' lever 135and the foot plate 137 are arranged within convenient reach of theoperator for the crowding mechanism, and. should the current be suddenlycut out of the motor or should it become desirable for any otherreason-to control the movement of the clipper, hel can instantly a plythe brake thereto.

Indepen ent controlling means are pro-l vided for the motors operatingthe hoisting, swingingl and crowding mechanisms, respectively. Thesecontrolling mechanisms are substantially the same and, therefore, wewill describe but one ofthe .same and .this description will applyto thethree controlling mechanisms. For the purposes of this description wewill use the controlling mechanism for the hoisting motors. It may benoted here that the arrangement of the hoisting mechanism is such as toenable two motors to be utilized and further to enable these motors tobe placed in the rear of the drivenvmechanism and in ai-position inwhichy they are not only out of the way, but in which the .weight willbe disposed toward the rear of the car. Further, two small motors can bestarted or stopped with much less effort than can` a single motor of ahorsepower equalV to the combined horse-powers.l of the two motors.Consequently, there is less acceleration with two motors than withon'e.y These two motors are controlled in common from a singlecontrolling mechanism, which mechanism is such as toautomaticallycontrol the successive cutting out of the resista-nce to increase thecurrent tothe motor, to so control the current to the motor as to causethe motor to exert a oon- .tinuous pressure or pull upon the dipper 4esegue ance, as by coming in contact 'With a ledge of rock, withoutpermitting the inotor to build up to the danger point. Further, thiscontrolling mechanism is such as to l Veak the main circuit and cut outthe motor entirely should the currentbecoine 'excessive for any reason,such., for instance, theI failure of seine part of the controllinginechf anism to operate.

In Figs. 4 and 5 the Inain circuit 'is indicated at 62 and is providedwith a generator 63 which is provided with a service switch -whichpoint. the circuit is divided, one part extending through the line(30,.through the hinged arin ot" a circuit breaker (37 tto a point (S8,thence through a clrcuit breake (3S) to a point 70, thence througha'solenoid'u forining" the electromagnetic operating means forthe-circuit breaker and closer A.. The current passes from the solenoidL through a line 71 to a point 72, thence upwardly vto a point 73 whereit is connected with the negative side of the niain circuit, thusconipleting the circuit through the solenoid (l.

asf

main circuit.

and closing the circuit breaker A in the The mechanism is now in itsoperative position and is under the control of vthe master controller X,which is ot the ordinary type. This master controller is, as usual,divided into two parts, right and left, indicated by R and L,respectively, and the operating handle operated in-one direction .or theother to actuate the inotor in a for- Ward or reverse direction. Whenthe handie has been turned in one direction, say to the left, a singlenotch the contact bars 74, and 70 will be inoved into engagement withthe contact 4fingers 77, 7 8 and 79,respectively. This act-ion oi themaster controller closes the controlling circuit through the circuitbreakers and closcrs on the opposite sides of the armature as follows:rlheI main circuit passes 'from the point 05 through the coil 91 of theoverload magnet, through the line 92, Icircuit breaker and closer A,line 93 to 87, thence through the vline 86 to the point Softhrough theline 83 and theoseveral circuit breakers and closers 84A to the .point82 where the circuit divides anda part lpasses through euch ofthesolenoids f and cv of lthe circuit breakers and velosers F and G ytothe point 81, Where the tvvo branches ot, thereirc'uitv againnnite andextend through the Iine to the Contact yfinger'78 `of themasterzeontroiler, thence matures oi both n'iotors. armature 10i?J thecircuit follows the line 102i through the contact bars 75 and 7 4,finger 77 to the point 72;l thence through the line 71 to the negatireside of the circuit at 73. The circuit is thus completed through theAsolenoids and, g/ and actuates the circuit breakers l" and G, closingthese circuit breakers and closcrs and coinpletingthe niain circuit,and, at the sain ltime, closing the circuit breakers and clpsgrs 88 and8%). The action oi thel solenoid ai. as served, at the saine tiine thecircuit breaker and closer A. was closed, to open the circuit breakerand closer 00, thus causing` the current to pass 'from the point` G8 tothe point v70 through a resistance 90, but maintaining a sutticientcurrent through the solenoid c to retain the circuit breaker and closerA in its closed position. These several steps having taken place themain circuit G2 extends lroin the point oi division (i5 through thesolenoid 91 of the overload circuit breaker and closer, through the line02, 'circuit breaker and closer A, line 93, solenoid 94 ot a circuitbreaker and closer 05 located in the controlling circuit of the secondcircuit breaker and closer B, as will bc hereimiitcr described, thencethrougrlithe line and the several sections ot' resistance indicated atR,

R3 and R4, through the line97 and solenoid 98 of asccond circuit breakerand closer 99" located in the controlling; circuit of the circuitbreaker .and closer B, thence through theline 100, through the circuitbreaker and closer (i. line 101 and the arinature 102 of the Inotor. Wehave here shown but one armature, but in the hoisting` mechanism thecircuity will pass through the ar- After leaving the through the circuitbreaker and closer lf, through the line 10%-, thence through the seriesfield 105 of the motor and from the field magnet to the line 10G and thenegative side ot the main circuit ($2 at the point-73, thus completingthe power circuit through the motors and operating the motors at theirslowest. speed,`as the current through all the resistance.

In Fig. 5 ofthe drawings the circuits are shown with the several part-sin the posi tions just described, but, in this drawing, the

`master controller X has been advanced to -the third notch, therebycutting out two i sections o'f the resistances and operating the motorat about haltl speed.' This operation takes place as follows: lll/henthe master controller has been moved to the third speedv the contactbars 107 and'108 Will be moved into contact with the contact fingers 109and 110, respectively. The master controller havingfbeen lirst'inoved tothe second notchV the controlling circuit will. beV completed 'throughthe second eircuitbreaker and closer B of the main circuit as follows.The curfl rent passes -from the point 87 of the line 93 isypassingupwardly through the line 86, as before, to I the point 85,thence upwardly through'the line 115 to the point 139 where it divides,

a part passing throu h thecircuit breaker 5 and closer 88, which actionof the solenoid f, through the line llflland circuit breaker and closer99, line 113, circuit breaker and closer 95, line 112 to the solenoid b,line 111 to the finger 109 of l the master controller and thence throughthe contact bars 76 and 74, finger 77 to the line 71' at 72 and thenceto the negative side of th line at 73, thus closing the circuit throughthe solenoid I) and actuating the same to r close the circuit breakerand closer` B and to open that circuit`breaker and closer. 84 of theline 83 which is connected with the solenoid'. As stated, the circuitdivides at the point 139, a part passing to the right through thecircuit breaker which has been closed by'the action of the solenoid g,through the line 140 to the point 141, thence4 through the line 142-tothe point y 143 of the line 83, thence through the solenoids f and g tothe line 80 and the master controller as before described, therebymaintaining the circuit breakersand closers F a'nd G closed. The circuitbreaker and closer B of the main lineA having beenclosed by the actionof the solenoid Zi permits the current to pass from the circuit breakerand closer A through line 116 to the circuit breaker and closer B,thence Vline 117, through the solenoid 118 of the circuit breaker andcloser 119, through the line 120 to the second section of resistance,vR', thence through the line 97, circuit 4 Jbreaker and closer G,armature 102, circuit V breaker and closer F, field magnets 105 to 40the negative side of the line, thus cutting out of the power circuit thefirst section of resistance, R. l

The movement of the master controller X to -the third notch brings thecontact bar 108 into contact with the finger 110 and closes the thirdcontrolling circuit to actuate the solenoid c to close the circuitbreaker and closer C, the circuit tracing in the same manner as in thecase of' the circuit'breaker and closer B, and to cut out a secondsection of resistance, R2, The circuit breakers and closers B, C, D andE are Y,closed successively in this manner until all the resistance hasbeen cut out and the main circuit is connected directly from the circuitbreaker and closer4 E to line 97 at 121.. It

will be; oticed that after passing through each of the circuit breakersA, B, C, D and E the power circuit Will pass through the solenoid 118 ofa magnetically operating circuit breaker and closer '119 which islocated in the controlling circuit of thc next succeeding circuitbreaker and closer inthe main line. The circuitbreakers and closers forthe controlling circuitsare so adjusted as been closed by the and closer89, y

through the as to be inoperative under Vn ormal current, but, when oneof the main circuit breakers and closers is first closed, the currentpass-- ing through the line is excessive and is sufficient to energizethe solenoid of the circuit breaker and closer in the next successivecontrolling circuit and break that circuit. So long as this controllingcircuit is broken the next succeeding circuit breaker and closer of themain line cannot be closed, re ardle'ss of the position of the mastercontrol er. As soon as the'motor has adjusted .itself to the increasedcurrent the solenoid of the circuit breaker and closer in thecontrolling circuit will be denergized and the circuit again cloed, thusenabling the next circuit breaker and closer in the main line to respondto the. i

movement ofthe master controller. B means of this controlling mechanismlit Wi l be apparent that even should the master controller be thrown onfull speed at one movement, the resistance will be cut out gradually, asthe motor acquires speed.

Should the excavating dipper strike an immovable or solidly embeddedrock or meetl with otherresistance of an unusual character the motorswill rapidly build up toward the danger point. In order to maintain'acon? tinuous pressure ork pull on the dipperand yet'avoid the danger ofburnin out the mot'ors we have provided means or cutting in a part ofthe resistance become abnormal. breaker and closer 99 located in thecontrollin circuit for the main line'circu'it breaker an closer B hasthe coil of its solenoid oonnectedinto the main power circuit beyondwhen the current'has' 'To this end thecircuit'v the last circuit breakerand closer E ofthe main line. This solenoid is adjusted to oper# ate,only `when the current in the motor reaches the vdanger point. When thecurrent reaches this point the circuit breaker and closer 99 is opened,thus breaking the' controlling circuit for the main line circuit breakerand'closer Band allowing that 4circuit' breaker and closer to open,therebybreaking the main circuit at that point and forcing the currentto 'pass from the first -circuit breaker and closerA of the main line Ithrough the line 93, circuit breaker and closer 94-95 and line 99 to thefirst section of resistance R and through all the resist-l ance to themotor. This excessive current operates the circuit breaker and closer`95 to oph the controlling circuit of the circuitv breaker and closer Band maintain the same open after the circuit breaker and closer 99 mayhave closed. Thus', the main line circuit breaker and closer B cannotagain close until the current"has been reduced to normal controllingcircuit112-113 closed, thus pervmitting the motor to again build up'inthe 1.25v and the circuit breaker and closer 95 of the eten-5c i such as.the Yfailure ci. some part of the controlling mechanism to operate, Wehave provided the overloadcircuit breakerl and closer 67-91, shown indetail in Fig. 6.' The solenoid 91 of this circuit breaker and closer isadjusted to be actuated only by an abnormal current, and, when soactuated, Will raise the hinged' Contact arm 67 and break thecontrolling circuit for the circuit breaker and closer A. of the mainline, thus cutting out the current entirely from the mo tor. Thecontrolling current for this circuit breaker and closer A divides at thepoint 122, before it reaches the contact inger 67, and passes through acoil 123, through the resistance 121i, line 125 to the contact linger 79of the master controller, thence through the Contact bars 7 6-74 andiinger 77l to the line 71at the 'point 72, thence upwardly to thenegative side of the main circuit at 7 3, thus maintaining a closedcircuit through the coil 123 so long as the master controller stands onor beyond the first notch. This current is-suilicient to hold theoverload circuit breaker and closer 'in its o en position, after it hasbeen once actuate and before this overload circuit breaker and closercan be again closed the master controller must be moved to zero to breakthe circuit through the coil 123.

We have so far described vthe action of the controlling mechanism whenthe controller handle is turned to the left, and it will be understoodthat, when the handle is turned to the right, the controlling circuitwill be closed through the solenoids circuit breakers and ciosers-H andI closed, thus completinghthe circuit through the armature 102 in t edirection opposite to that heretofore described. Otherwise, the opera,tion is `the saine. It will also be obvious that the amount ot1resistance and the num vber of circuit breakers and closures interposedin the main line may be varied ac cording to existing conditions and therequirernents ci' the machine to which the mechanism is tol be applied.The detail con struction of 'this controlling mechanism does not form apart of our invention and we have, therefore, described the same only ina general Way, suiiicient, however,to enable its operation and themanner in which it is combined with the excavating mechanism to beunderstood. In applying the controlling mechanisms to the motorsdescribed in connection with the excavatingmechanisun eachccntrollingmechanism is arranged entirely separate vtroni the other coutroliingmechanism and the circuit breakers and closers are mounted on plates 126ci nonoonducting mater-iai and the resistance, which is put un in theusual manner, mounted in the rear ci the supporting plates 126, as shownat 127. The main circuit breaker t3 is arranged near the front h and iand the tion, and it will be apparent that the clos-- ing of the serviceswitch G3 serves to close the circuit breaker and closer A ofthe maincircuit and that, as soon as the master controller has been actuated toclose the controlling circuit through the solenoids f and g and thusclose the switches F and Gr, the.

circuit will be completed through all the vresist-ances and through themotor, starting the machine at the lowest speed; that, as the 'mastercontroller is advanced notch by notch, the circuit breakers and closersfor the main line are successively actuated and lthe actuation of eachsuccessive circuit breaker and closer cuts out an additional amount ofresistance until, when the circuit breakerl and closer E has beenclosed, the entire resistance'will have been cut out' and the motor willbe running at full speed. it

will also be apparent that, if .the master.

controller be rapidi advanced from notch to notch, the controllingmechanism Willautomaticaily revent the operation ci' the succeedingcircuit breaker and closer for the main circuit until the motor hasadjusted itself amount of current; that, shouid the excavating mechanismor other part ci the machinery meet 'with abnormal resistance, such asto cause-the motor to build. up very rapidly,`the controlling circuitlll, 112, 113

vand iiiffor the circult bre-alter and einserv B in the main circuitwill be broken, thus causing the main circuit to be broken at l5, and inthis lnanner cutting in again aii the resistance, and allowing the motoreither to continue its operation at a iower rate of speed or to come tca standstili, but mainu taining a constant torque in the motor andcausing the saine to exert a continuous pull or pressure upon theexcavating member;` that, by means of this controlling mechan-v ism theamount of current admitted to the motor is regulated by the movement oftbd excavating member or dippcr, thereby air i tomatlcally regulatingthe amount oit current admitted to the motor under various operatingconditions, as when the' excavating member or flipper encounters anobstruction or an excessive resistance to its movement; that, should thecurrent become excessive for any reason, .such as the failure ct somepart o the controliing-niechanism to operate, the'main circuit will beautomatically broken and the curr nt cut out of the motor entirely g.and that it willi necesto receive the additional' ics e esente l sary toreturn the master controller to zero before the circuit can again becompleted. through :the motor. It will also be apparent that We haveprovided an electrical driving mechanism for an excavating machine whichcan be readily substituted for the or dinary steam driving mechanism ofa steam driven excavating machine; that the driving mechanism is soarranged as to occupy a minimum amount of space and is arranged in sucha manner as to secure the highest degree of efficiency; that thecontrolling mechanism and the resistance are arranged in the rear of themotors where they will he out of the Way; and that the wholeconstruction and arrangement is such as to distribute the weight to thebest possible advantage.

As above stated, we do not claim as our invention the specificelectrical mechanism herein shown and described, but we do claim to bethe first to have provided a power ex cavating machine with electricdriving mechanism; and to so control this mechanism from the excavatingmechanism that the motors will exert a continuous pull against a fixedresistance, that is, if tlfe excavating member or dipper meets with anexcessive amount of resistanceto its movement, the motor will be allowedto build up to a predeterminedpoint only and then resistance will be cutinto the circuit in suiiicient qualitities to materially reduce theamount of current admitted to the motors, but to permit the motors ltocontinue their operation at a lower rate vof speed, or vto come to atempo rary stop, and to maintain a constant: torque in the motor, thusexerting a continuous pull or pressure upon the excavating member.

lVhilc we have particularly described the cont-rolling means for thehoisting mechanism, it will be understood that this same con`trolling'means is. applied, with but slight' modifications, to both theswinging mechanism and the crowding mechanism and these modificationsare of such a minor character that it is unnecessary to herein describethe same. The controlling means abovey described in connection with thehoisting mechanism is of particular value in connection with thecrowding mechanism in that it is in this crowding mechanism that it ismore often desirable to cause the clipper toJexert a Steady, continuouspull againstv the work, even though the resistance offered to the dippermay be such as to entirely prevent its' movement. When such resistanceis offered 'to the dipper the current admitted to the motor is socontrolled that a continuous torque is kept up in the motor, which issuiiicient to move the motor at a low rate of speed, but is notsuiiicient to damage the motor should the armature come Ato a temporarystop, as, when the dipper strikes a ledge of rock.

The mechanism herein shown and described is chosen for the purpose ofillustration onlyand-it will be obvious that many changes might be madetherein, and We, therefore, Wish it to be understood tha-t We do notdesire to be limited to the details of construction shown and described,for 'obvious modifications Will occur to a person skilled in the art.

Having thus fully described our invention, what we claim as vnew anddesire to secure by Letters Patent, is r l. In anexcavating machine, thecombination, with an excavating member, a motor for actuating saidexcavatin member, a motor circuit, and a master-controller for saidcircuit, of means controlled b said excavatingmember for cuttingresistance into said circuit, and meansto prevent the cutting out of theresistancerfrom said circuit before said master-conti'oller has beenmoved to zero. y f

2. In an excavating machine, the combination, with an excavating memberhaving a plurality of movements, of a separate motor for imparting eachof said movements to 'said excavating member, independent automaticcontrolling mechanism for each of said motors, an independent `mastercontroller for each of said motors, `smid master 4controllers beinggrouped about a common point and arranged within reach of the operatorfrom a single position.

3. In an excavating machine, the combination, with a frame, and anexcavating member, of a Ashaft arranged transversely Vto said frame,means for operatively connecting said shaft to said excavating member,gears mounted on said shaft near the opposite ends thereof,other shaftsarranged near the opposite sides of said frame, pinions mounted on saidother shafts and meshing with the respective gears on saidfirstanentioned shaft, and means for actuating the last-mentioned shaftsin unison.

et. In an excavating machine, the combination, with a frame, and anexcavating member, of a shaft arranged transversely to said frame, meansfor operatively connecting said shaft to said excavating mem ber, gearsmounted on vsaid shaft near the opposite ends thereof, a shaft arran 'ednear each side of said frame and extending longitudinally thereto,pinions mounted on said longitudinal shafts and: meshing with saidgears, an electric motor connected to each of said longitudinal shafts,and means for controlling said motors in common.

5. ln an excavating machine, the combination, with a frame, andanexcavating member, of a shaft arranged transversely to said frame',means for operatively con- -necting said shaft to said excavatingmember., gears .mounted on said shaft near the opposite endsthereof, ashaft arranged near each side olf said 'frame and extending longil tothe shaft of .fsaid hoissting-drn1n, and a tudinally thereto, pinionsmounted on saitl longitudinal Shafts and n'ieehingr with said gears, oneloetrifmotor connected to each of said longitudinal shafts, means -forrox:- trolling snitl motore inl Common, o eee-ond transvorf-ie Shaftarranged in the rear oll the 4tiret-mentioneil tran.-s\'erse shaft,means i'or operatively,Y Connecting said seemnl transA verse shaft tosaid exicavating member, an elet-trie motor'- arranged between saidlongr tndinal shafls anl ope 'atirely connected to :said seronrltransvezse shaft, an l moans lor controlling saairl motor independentlyof the. first-mentioned motors.

(3. ln on excavating machine, the Combination, with a main frame, anexcavating member, a nhaft, anti a` (lrlnn mounted on salti shaft. allol Standard design, of a Supporting fragile znlapiell to be removablymount-eil nin/1n aanl main lralne ai'nl support said shaft, n motormounted on said main frame in the rear of ,miirl Supporting frame,

and menne for operatively Connecting said motor to said shaft. i

7. In an excavating maohin. the combi nntiomwitii a main iframe, ano anema-Yatw ing member, of a hoisting-drinn mounted on said main frame, aSwinging-ordm mounted on said moin frame in the rear of Saidhoif'sting'felrnm, motor mounted` on Said moin lframe in the rear ofvsaid swingingdrnm and operatively oonneoted' thereto, another motormounted on Said moin frame inthe rear of said swinging-drinn, and meansfor operatively connecting said laestmentioned motor to saidhoistingdrnm.

8. ln an excavating machine, the combination, with a-niain iframe,and-an. eXCavat ing lnenllxer. of a' ,shaft arranged transversely tomild main frame, a hoisting-drinn mounted on said lishalft, a seeonlshaft mounted on sai@ main raine swingingilrnm mounted on,Qzrirlvsecontl shaft, n motor arrangeol Hr-of said Swinging-drum anfloperatively connecteti to said seeonfl Shaft, longitudinal Shaftsarranged on each sitle of said motor, operatively connected to saidlirst-mentioi1etl Shaft angl extending to points in the rear of Saidmotor, and o motor connected to each of said longii'zinlinal shafts.

9. ln an excavating machine, the eoniloinotion, with a main frame, andan excavating member, o shaft, a hoistingalrnm monniefl on Hariri shaft,a supporting frame mounted on said main frame in the rear of sontshaft., a. swinging-drinn mounted on saiel supportingrmne in a pianeabove the rSv-- inentiones shaft, a motor mounted on main from@ in therear of sind supporting, frame and operatively connected. to sani VS\\'inging-cl1'um, longitudinal shafts mount ed on said main frame oneach side of said suppertingyrmne and; operatively eoim'eeedV motorconnertefl to each of Said longitntlinal shafts.

10. ln an excavating machine, the oomlnnatlon, with n mann frame, and anexcavating member, of a sli-rift, o hoisting-drinn `mounted on Sani.shaft, a supporting-frame n nmntecl on s-:aid main 'frame in the rearofSani sha't't, a mvingingdrum mounted on said su1porting-frame in a planeahovethe first-mentioned, shaft, motor mounted vin saitl main frame inthe rear of Said supportingg-lirarne anti opera-tively connected to saidswinging-(kuni, longitudinal Shafts in0unt ed on Said main frame oneaoli side of said elimiorting-frame and operatively eonneotetl to thesha't of said hoisting-drum, a motor connected toeaeh of saidlongitudinal shafts, and autoina'iio controlling mechanism for all o'lsaid niotors mounted on the main frame in the rear of thelaei-me'nt-ione@` motor.

l1. ln an excavating machine, a main frame, ay boom' movably mountednear the forward enti of Said frame, and an excavating' flipper Carriedhy Said boom, hoisting and swinging drums inounte on said main frame inthe rear of Saitloooni, elec-trio motors mounted on said main frame inthe rear of Said drinne and operatively connected to saiti hoisting,land f5 inging drome, respectively, and controlling mechanism for Saidmotors Supported on said frame in the rear of said motors.

lf3. in anV excavating nio-chine, a main iframe, a boom mounted at the'forwarfl end thereof, an excavating clipper carried hy ,Sani boom,hoisting (lrun'i mounted on seni moin frame in the reni: of Sani boom, eshaftrolal'ahly mounted on Said main 'frame in the rear of said hoistingdrinn and operotively connected thereto, bevel gears carried by theopposite.v ends of seid shaft, longitudinally arranged shorts supportednear the opposite sides of emol ro. 'n rame, e bevel pinion secured tothe forward enel of 'each of sani shafts an-fl inee'iing with 'therespective bevel gears, an eleetriomotor operatively eonneetecl to therear enel of each of said Shafts, a removable supporting' from@ mountedon seid moin frame in the rear o'lsaid hoisting drum intl between Sollongitudinal shafts, o swinging drum meer totaly mounted on soleisupporting frame, en eleetrio meier supported on seid. main frame in therear ol" said Supporting 'iframe enelv tween swirl longitntlinal shaft@and operetively connected to Said si, inging clrnin, automaticcontrolling; mechanism for Said motors mounted. on said main "freinenein." the rear end thereof, and master controllers for said motorssupported neaiilie forward end of said main treme.

13. n an exeorating machine, the VJomhinotion, with. boom, enel o irpermount- CBG ed thereon and movable relatively thereto,

of an electric motor mounted on said boom and operatively connected tosaid dpper, and means'controlled by the movement of lseid clipper forcutting out a part only of rthe current from said motor.

'14. In anzexcavathin machine, the combination, Wit-h' a bo yportion, ashaft mounted thereon, means for rotating said shaft, a drum mounted onsaid shaft, frio.v

tion clutch mechanismv for connecting said drum to s aid sha-ft, and apower cylinder for actuating said clutch mechanism, ofan air compressormounted on lsaid body portion and connected with said power cylinder,and v15 GEORGE W. KING. HARRY J. BARNHART. CHARLES B. KING.

i Witnesses:

'W. R. WADDELL, C. M; WRIGHT.

